Is there anyone in the Donald Trump administration who’s not under investigation? That’s become the defining question of Trump’s tenure, as the Special Counsel probe into his own criminal activities has become just one of dozens overlapping and separate investigations into Trump’s various advisers, associates, cabinet members, and even family members. Now Trump’s senior adviser Kellyanne Conway is officially under congressional investigation.

This was easy to see coming, after Health and Human Services Secretary Tom Price was forced to resign as a result of his scandalous private chartered jet travel. Kellyanne Conway was on some of those wastefully expensive flights with Price, despite having no valid reason to be there. Now Congressman Elijah Cummings, the ranking member of the House Oversight Committee, is investigating the extent of Conway’s inappropriate luxury travel, according to an ABC News report (link). This is crucial for a few reasons.

The decision by Cummings to pursue this suggests that Conway may have been making a habit of taking luxury flights on the taxpayer dime which went beyond merely hitching a ride on some of Price’s inappropriate flights. If it turns out one of Trump’s senior White House advisers was engaging in the same kind of fraudulent activity that forced a cabinet member to resign, it’ll put the Democrats in a strong position to demand that Conway resign as well. If she refuses to, and if Trump fails to fire her, then the chartered flights scandal will continue to grow worse for Trump; he’ll have essentially scapegoated Price for nothing.

In addition, this investigation into Kellyanne Conway may serve to pry loose information about other Trump advisers who may have been engaging in the same corrupt behavior. If it becomes clear that this kind of scandalous luxury travel was the norm for Donald Trump’s own people who are personally close to him, rather than merely poor decision making on the part of one or more cabinet members, it gets even worse for him.